1. Field of the Invention
The present invention relates to an automatic transmission for motor vehicles, comprising an input shaft driven by a torque converter, two counter shafts alternately driveable by the input shaft, an output element and gears grouped in pairs on the shafts for driving the output element from the input shaft via one or the other of the counter shafts, at least one gear in each gear pair co-operating between the input shaft and the respective countershaft being freely rotatably mounted on its associated shaft and being lockable to the shaft by means of a friction clutch.
2. Description of the Related Art
Automatic transmissions of this type, i.e. those provided with counter shafts, are simpler and less expensive to manufacture, especially for manufacturers already producing manual transmissions, than are the conventional type of automatic transmission using interconnected sets of planetary gears, wherein the sun gear and/or annulus and cage are locked or released with the aid of brakes and interleaved clutches. Transmissions with twin counter shafts can also be designed significantly shorter in the axial direction than transmissions based on planetary gearing, and this makes them particularly suited for use in front-wheel drive vehicles with transverse engines.